Thermally stable polyindanyl polymers derived from phenylene oxides and process for making the same

ABSTRACT

This invention relates to a group of polyindanyl polymers derived from disubstituted phenylene oxides. When suitably catalyzed, the monomers of the invention are polymerized to materials that exhibit improved thermal stability, chemical resistance and mechanical flexibility. These polymeric products can be employed as adhesives, coating materials, and laminating resins; and, when suitably reinforced, they can be used as structural plastics.

United States Patent [191 Neville [111 3,725,346 [451 Apr. 3, 1973 [54] THERMALLY STABLE POLYINDANYL POLYMERS DERIVED FROM PHENYLENE OXIDES AND PROCESS FOR MAKING THE SAME [75] Inventor: Roy G. Neville, San Carlos, Calif.

[73] Assignee: Bechtel International Corporation [22] Filed: Aug. 9, 1971 211 Appl. No.: 170,340

Related US. Application Data [62] Division of Ser. No. 31,358, April 23, 1970, Pat. No.

[52] U.S. Cl ..260/47 UA, 117/132, 260/47 R, 260/612 R [51] Int. Cl. ..C08f 7/02 [58] Field of Search ..260/612 R, 47 R, 47 UA [5 6] References Cited FOREIGN PATENTS OR APPLICATIONS 241,148 l0/l962 Australia ..260/6l3R Primary Examiner-James A. Seidleck Assistant Examiner-C. A. Henderson, Jr, Attorney-Carl Hoppe et al.

57 ABSTRACT 3 Claims, No Drawings THERMALLY STABLE POLYINDANYL POLYMERS DERIVED FROM PIIENYLENE OXIDES AND PROCESS FOR MAKING THE SAME This application is a division of my pending application Ser. No. 31 358, filed Apr.-23, 1970 now U.S. Pat. No. 3,663,625 ofMay 16, 1972.

BACKGROUND OF THE INVENTION In the prior art, a-methylvinyl-(i.e. isopropenyl) and/or a-phenylvinyl-substituted aromatic compounds (typified by a-methylstyrene or l,l-dipheylethylene) are polymerized by means ,of free radical catalysts, or Lewis acid catalysts, to yield polymers which possess linear aliphatic chains in their polymer structure. Such aliphatic chains usually exhibit poor resistance to heat and chemical attack, because hydrocarbon chains are not noted for their thermal stability.

Although some high temperature resistant resins such as the polyimides, polybenzimidazo'l es, polyquirioxalines, and polypyrrones have provided some degree of success, these polymers required meticulous control of stoichiometry to attain usable molecular weights. At this stage the oligomer (i.e. low molecular weight polymer) is usually only sparingly soluble (or insoluble) even in exotic solvents. Final cure to practicable and useful polymeric materials involves elimination of solvents and liberation of small volatile molecules (e.g. water produced in the act of polymerization), thus producing an intrinsically porous material.

SUMMARY OF THE INVENTION This disclosure provides details of the composition and method of preparation of two closely related families of homologous bis (a-substituted-vinyl) monomeric compounds containing phenylene oxide backbones, and of polymerizing the same. The invention comprises the synthesis of solubledifun'ctional bis (asubstituted-vinyl) monomers which may be polymerized in place to produce polymers having long chains and low cross-link density without simultaneous liberation of small molecules.

Typical examples of the monomers of this invention are:

bis[4( l-methylvinyl)phenyl] ether I ,4-bis[4( 1-methylvinyl)phenoxyjbenzene bis {4[4( l-methylvinyl)phenoxy1phenyl ether bis[4( l-phenylvinyl)phenyl] ether l,4-bis[4( l-phenylvinyl)phenoxy]benzene bis{4[4( l-phenylvinyl)phenoxylphenyl }ether The chemical structures of these disubstituted monomers are given elsewhere in this disclosure.

The invention herein disclosed describes the preparation of thermally-resistant polymers which are formed by a chemical mechanism that does not release small molecules (e.g; water) as by-products of the polymer-forming process. Moreover, by suitable choice of the catalyst system, these a-substituted vinyl derivatives can be made to polymerize, by ring closure, to thermally-resistant indanyl groups, rather than to the less thermally-stable, conventional polystyrene-type straight-chain aliphatic polymer structure. Thus, the polymers of this invention are composed not only of thermally-stable backbones, but also of thermallystable connecting links, which latter are extremely uncommon and are formed by an addition and rearrangement mechanism which does not involve the elimination ofvola tile small molecules.

This invention includes the two related families of substituted divinyl monomers, having long flexible chains and low polymer cross-link density, the generic structure of which may be generally characterized as follows:

where:

Ar'is a homocyclic aromatic structure selected from the class comprising:

R is selected from the class consisting of straightchain alkyl groups (having from one to five carbon atoms), phenyl groups, or fluoroalkyl groups (having from one to five carbon atoms); and R is selected from the class comprising H or straightchain alkyl groups having from one to five carbon atoms, n being an integer such as 2, 3, or 4.

DETAILED DESCRIPTION OF INVENTION The inventive concept disclosed herein includes a method for obtaining two groups of homologous bisisopropenyl and bis-phenylvinyl monomeric compounds, capable of polymerization, having the structure expressed by chemical symbols in equation 3 below. Substituted-vinyl compounds of the general nature thus symbolized can be prepared by a series of sequential reactions which are broadly characterized by equations 1, 2 and 3 below and illustrated by Examples I through lV. First, the parent aryl ether or polyaryl ether is treated with an organic acid halide (usually a chloride), e.g. an aliphatic or an aromatic acid halide, using appropriate procedures known to the prior art including the Friedel-Crafts procedure. This yields a disubstituted aryl derivative of the aryl ether (which is usually oriented para,para'), or polyaryl polyether according to the general reaction:

Structure l Structure 1 is then isolated, suitably purified by recrystallization as is hereinafter described, then treated with a Grignard reagent to yield a bis-alcohol intermediate:

Structure II Structure III Polymerization of compounds of the type of structure III can readily be effected by treating the bis(substituted-vinyl) monomers with Lewis acid catalysts, the most suitable being those selected from the class of metal halides typified by stannic chloride (Sn C1 aluminum chloride (A1 C1,), ferric chloride (Fe C1 phosphorus trichloride (PCl boron trifluoride (BF and the like.

The temperature and pressure required for cure will necessarily vary according to the particular monomer being polymerized. Thus, the pressure can range from 1 to 200 psi, and the temperature can be within the range of -30C to about 250C in order to provide a satisfactory cure. Preferable conditions are 15 psi and 80 to 180C.

The following are specific examples of the preparation of the intermediate and final compounds of this invention. Wherever reference is made by use of a Roman numeral to a monomer, the structural formula of the monomer will be found on either Table I or Table I1.

EXAMPLE 1 Bis(4-acetylphenyl) ether Acetyl chloride (454.0 g, 5.77 moles), finely powdered anhydrous aluminum chloride (908.0 g, 6.8 moles), and dichloromethane (900 ml) were cooled to 30C. Phenyl ether (467.0 g, 2.75 moles) in dichloromethane (300 ml) was added slowly, with stirring, during 60 min, while the temperature was maintained at approximately 30C. The mixture was stirred at 10C for 2 hrs, then left unstirred at 20C overnight'The dark-red solution was poured onto crushed ice (ca. 3 kg), extracted with dichloromethane, and the extract was washed to pH 7 with water. The organic layer was dried over anhydrous magnesium sulfate, filtered, and the solvent was removed by means of a rotary evaporator. The cream-colored solid was recrystd. from ethanol to give 628.0 g (90 percent) of colorless platelets, mp 102.5C. The infrared spectrum showed a strong absorption band at 1685 cm (C=O). C I-1 0543) Calcd. C 75.57 H 5.55 Found C 75.58 H 5.52

EXAMPLE II Bis[4( 1-hydroxy-l-phenylethyl)phenyl] ether A warm (30-35C) solution of l(4,4'-diacetyldiphenyl ether) (102.0 g. 0.4 mole) in dry benzene (600 ml) and ethyl ether 100 ml) was purged with dry nitrogen, and then phenylmagnesium bromide (3 M, 533 ml, 1.60 moles) (100 percent excess) was added dropwise with stirring during 2 hr. The mixture was heated at reflux (60C) for min, then allowed to cool to room temp. with stirring. A sample (5 ml) was removed, shaken with dil. I-lCl, the organic layer was separated, dried with anhydrous magnesium sulfate, filtered, and evaporated. The infrared spectrum showed no absorption due to the carbonyl group, indicating that reaction with the Grignard reagent was complete. The Grignard complex was decomposed by pouring onto crushed ice (ca. 500 g), then hydrochloric acid (10 percent) was added to pH 7. The organic layer was washed with water; and the original aqueous layer was extracted with benzene (200 ml), washed with water, then added to the organic solution. After drying over anhydrous magnesium sulfate, the solvent was removed by means of a rotary evaporator and a viscous pale-yellow oil (164 g, percent) remained. No elemental analysis data were obtained. The structure of XI was inferred from its method of preparation, and subsequent dehydration to the alkene. The infrared spectrum of XI showed strong absorption at 3560 cm (-OH), and at 3420 cm. (PI-bonded OH). The usual aryl ether peak was strong in the region 1230-1250 cm'.

EXAMPLE Ill Bis[4( l -phenylvinyl)phenyl] ether X1 g, 0.29 moles) was dissolved in warm xylene (750 ml) then placed in a l-liter flask equipped with a reflux condenser and Dean-stark watertrap. Concentrated orthophosphoric acid (1.2 g) was added, and the solution was heated at reflux for 5 hr when 10.7 ml of water had collected in the trap (theory, 10.8 ml). Solid sodium bicarbonate (25 g) was added to the hot solution, and the reaction flask was shaken for 10 min, or until no further carbon dioxide was evolved. The solution was filtered hot, and the filtrate was evaporated to dryness. The pale-yellow solid (109.0 g, 99 percent) was recrystd. from boiling ethanol to yield XII as white iridescent meedles (99.6 g, 91.1 percent), mp 138.5C. The infrared spectrum showed a sharp substituted-ethylene peak at 1610 cm", aromatic bands at 1598 and 1502 cm", and an aryl ether absorption band at 1255 cm.

C I-1, 0 (350.4) Calcd. C 89.84 H 5.88

Found C 89.73 H 5.85

EXAMPLE IV a-Methylvinyl (isopropenyl) derivatives of phenylene oxides were similarly prepared from acetyl chloride to produce the diacetyl derivative of the phenylene oxide, followed by treatment with methylmagnesium bromide, and elimination of the elements of water (as above) to produce the isopropenyl derivative.

EXAMPLE V Polymerization of lsopropenyl Derivatives The above described di-isopropenyl monomers were polymerized to polymers containing indanyl. groups by dissolving the appropriate monomers in methylene chloride (or some other appropriate non-reactive solvent) then adding the Lewis acid catalyst, mixing and heating in a circulating air oven. As an example, bis[4( l-methylvinyl)phenyl] ether (1.25 g, 0.005 mole) was dissolved in methylene chloride (10 ml) at 20C. A solution of stannic chloride (2.0 ml of 1.0 percent solution in methylene chloride) was added, and the methylene chloride was evaporated. The viscous oligomer was first heated at 60.C..for 1 hour, followed by 3 hours at 120C, followed by 1 hour at 180C. The product was a clear brown polymer which was completely insoluble in common organic solvents at room temperature e.g. acetone, benzene, chloroform, methylene chloride, dimethylformamide, dimethyl sulfoxide, and the like, and even at the boiling point of the solvents.

EXAMPLE VI Differential Thermal Analysis Data Differential thermal analysis tests were carried out in air or Differentialthermal analysis tests were carried out in air or nitrogen at a heating rate of 10C. per minute. Specimens of cured polymeric l,4-bis[4 (l-methylvinyl)phenoxy1-benzene showed the following weight losses: l per cent weight loss at 476C 50 per cent weight loss at 580C The above data show that these outstanding thermal stabilities are due to a polymer structure which is other than the conventional linear aliphatic vinyl-type" polymer. It is known that a-methylstyrene will cyclize to l,l,3-trimethyl-3-phenylindane (which is thermally stable); when heated with a strong Lewis acid catalyst; and since the structures of the monomers disclosed herein are chemically identical with a-methylstyrene, as far as their terminal groups are concerned, it is inferred that the chemical groups connecting the phenylene oxide chains are substituted indanyl rings. Infrared spectra of the polymers are indicative of this indanyl structure. The polymers disclosed herein most probably possess the following structure:

The above is an example of a substituted indanyl connecting group in polyphenylene oxide polymer chain.

The following Tables 1 and 2 set forth various monomers from which novel polymers can be produced by the present invention. Reference to these monomers is made by the Roman numeral designation given in the tables.

The polymers thus formed exhibit good adhesion to aluminum and steel. They also exhibit good mechanical flexibility.

The important point of the invention disclosed herein is that the previously largely intractable thermally-stable polyphenylene oxides can now be linked together by thermally-stable indanyl structures. Polymeric structures can thus be carefully built up from monomers of known composition and purity to produce polymers of predictable structure. Hitherto the polyphenylene oxide polymers known have been formed by other totally different techniques; and they have been exceedingly difficult and impractical to use in practical applications because of their insolubility, intractability, and the fact that the polyphenylene polymers usually had to be formed in situ. The monomers of this invention allow polyphenylene polymers to be formed using standard and practical techniques; thus expanding the use of polyphenylenes and allowing their use inhitherto impractical situations.

While the particular details set forth above are fully capable of attaining the objects and providing the advantages suggested herein, the specific materials and methods thus disclosed are merely illustrative and can be varied to produce the same results without departing from the scope of the inventive concept as defined in the appended claims.

sisting of a metal halide of an element in any one of Groups Ill, IV, V and VIII of the Periodic Table; the compound having the chemical structure:

wherein:

Ar is a homocyclic aromatic ring including the phenylene group;

R is selected from the group consisting of phenyl, biphenylyl, naphthyl, and straight-chain alkyl groups having from one to five carbon atoms;

R is selected from the group consisting of H and a straight-chain alkyl radical having from 1 to 5 carbon atoms;

and n is an integer from I to 6.

2. A homopolymer including a methyl group and a phenylindanyl group in its final structure and derived from a compound of the structure set fourth in claim 1 above, and produced by reacting (treating) the compound with a Lewis acid catalyst as defined in claim 1.

3. A thermally-stable, chemically resistant and mechanically flexible homopolymer derived from a compound having the chemical structure:

L JD

wherein:

' Ar is a homocyclic aromatic ring including the phenylene group;

R is selected from the group consisting of phenyl, biphenylyl, naphthyl, and straight-chain alkyl groups having from one to five carbon atoms;

R is selected from the group consisting of H and a straight-chain alkyl radical having from one to five carbon atoms;

and n is an integer from I to 6;

by reacting said compound with a Lewis acid catalyst selected from the group consisting of a metal halide of an element in any of Groups III, IV, V and VIII of the Periodic Table to produce a homopolymer having at least two polyphenylene oxide groups linked together by a thermally-stable substituted indanyl group. 

2. A homopolymer including a methyl group and a phenylindanyl group in its final structure and derived from a compound of the structure set fourth in claim 1 above, and produced by reacting (treating) the compound with a Lewis acid catalyst as defined in claim
 1. 3. A thermally-stable, chemically resistant and mechanically flexible homopolymer derived from a compound having the chemical structure: wherein: Ar is a homocyclic aromatic ring including the phenylene group; R is selected from the group consisting of phenyl, biphenylyl, naphthyl, and straight-chain alkyl groups having from one to five carbon atoms; R'' is selected from the group consisting of H and a straight-chain alkyl radical having from one to five carbon atoms; and n is an integer from 1 to 6; by reacting said compound with a Lewis acid catalyst selected from the group consisting of a metal halide of an element in any of Groups III, IV, V and VIII of the Periodic Table to produce a homopolymer having at least two polyphenylene oxide groups linked together by a thermally-stable substituted indanyl group. 